scholarly journals A Novel LC-MS/MS Method for Improving Long-Term Stability of Retinol in Dried Blood Spots and Quantification of Its Levels

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1857-1857
Author(s):  
Min Zhang ◽  
Fang Wang ◽  
Shuyi Zhang ◽  
Jian Yang ◽  
Xiaodai Cui ◽  
...  
Keyword(s):  
Vitamin A ◽  
Research And Development ◽  
Development Program ◽  
Dried Blood Spots ◽  
Calibration Model ◽  
Reference Ranges ◽  
Blood Spots ◽  
Relative Standard ◽  
Plasma Retinol ◽  
Retinol Concentration

Abstract Objectives To establish an accurate and reliable method for stabilizing vitamin A (retinol) in Dried blood spots (DBS), quantifying and comparing DBS retinol concentrations with their equivalent plasma retinol levels. Methods Antioxidants pretreated on paper combined with vacuum treatment were used to increase retinol stability on DBS. A surrogate matrix of whole blood prepared using mixture of human erythrocytes and 2% BSA in PBS was firstly used in DBS retinol determination based on the fact that retinol is excluded from erythrocytes. Results DBS retinol was stable during 120 min of air drying and 30 days of room-temperature storage. The method was linear in the concentration range of 0.04–300 μg/mL. Accuracy was calibrated using two National Institute of Standards and Technology (NIST) calibrants generated serum at concentrations of 0.1962 and 0.3948 g/mL, relative errors (RE% values) of 0.07% and 4.95% were found, respectively. Both the between-run (n = 5) and within-run (n = 6) precision (relative standard deviations, RSD%) were below 8.42%. The spiked recoveries at 3 concentrations ranged from 86.48% to 98.13%. A reliable calibration model was first developed to convert DBS retinol concentration to the equivalent plasma retinol concentration. Conclusions The validated method can be applied to the nutritional assessment of vitamin A, using the established calibration model, DBS retinol can compare with clinical reference ranges and with studies using serum or plasma samples. Funding Sources The National Key Research and Development Program of China (2018YFC1002503); The National Natural Science Foundation of China (Grant No. 81,400,848, 81,701,441); The CAMS Initiative for Innovative Medicine (2016-I2M-1–008); The Beijing municipal program of medical research (Grant No. 2016–04); The National Key Research and Development Program of China (No. 2016YFC1306204).

scholarly journals Vitamin A status in Cuban children aged 6–11 years

2008 ◽  
Vol 11 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Consuelo Macías-Matos ◽  
Gisela Pita-Rodríguez ◽  
Pedro Monterrey-Gutiérrez ◽  
José Reboso-Pérez
Keyword(s):  
Vitamin A ◽  
Fruits And Vegetables ◽  
Sixth Grade ◽  
Eastern Region ◽  
First Semester ◽  
Vitamin A Status ◽  
Small Variety ◽  
Mother And Child ◽  
Plasma Retinol ◽  
Retinol Concentration

AbstractObjective and settingA nationwide study was performed in Cuba to assess vitamin A status and the intake of vitamin-A-providing foods in children aged 6–11 years.Design and subjectsThe sample comprised 1191 schoolchildren from first to sixth grade, both sexes, from municipalities randomly selected from the five eastern provinces of Cuba in 2002 (first semester) and from the four western and four central provinces in 2003 (first semester). A food-frequency questionnaire was completed by 2038 mother-and-child pairs.ResultsMean (±standard deviation) plasma retinol concentrations were 1.77 ± 0.48 μmol l−1in the western, 2.01 ± 0.56 μmol l−1in the central and 1.40 ± 0.41 μmol l−1in the eastern region. No child had plasma retinol concentration below 0.35 μmol l−1, indicative of a high risk of clinical deficiency. Subclinical deficiency, plasma retinol concentration of 0.35–0.7 μmol l−1, was seen in <2% of subjects in all three regions and was <5% even in the two provinces with the worst vitamin A status (Guantánamo, 4.6%; Las Tunas, 3.0%). Adequate status (>1.05 μmol l−1) was present in >90% of subjects in all western and central provinces, and in one of the eastern provinces (Holguín), whereas in the four remaining eastern provinces, adequate status was present in >75%. Only nine fruits and vegetables were consumed frequently (>3 times per week) by >50% of children. Thirty-seven per cent regularly consumed a supplement containing vitamin A.ConclusionsMost Cuban children aged 6–11 years had adequate vitamin A status. Consumption of foods rich in vitamin and provitamin A, especially vegetables, was frequent but limited to a small variety of foods.

scholarly journals DNA Methylation at Birth Predicts Intellectual Functioning and Autism Features in Children with Fragile X Syndrome

2020 ◽  
Vol 21 (20) ◽  
pp. 7735
Author(s):  
Claudine M Kraan ◽  
Emma K Baker ◽  
Marta Arpone ◽  
Minh Bui ◽  
Ling Ling ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Single Gene ◽  
Intellectual Functioning ◽  
Dried Blood Spots ◽  
Reference Ranges ◽  
Mrna Levels ◽  
Blood Spots ◽  
Fmr1 Mrna

Fragile X syndrome (FXS) is a leading single-gene cause of intellectual disability (ID) with autism features. This study analysed diagnostic and prognostic utility of the Fragile X-Related Epigenetic Element 2 DNA methylation (FREE2m) assessed by Methylation Specific-Quantitative Melt Analysis and the EpiTYPER system, in retrospectively retrieved newborn blood spots (NBS) and newly created dried blood spots (DBS) from 65 children with FXS (~2–17 years). A further 168 NBS from infants from the general population were used to establish control reference ranges, in both sexes. FREE2m analysis showed sensitivity and specificity approaching 100%. In FXS males, NBS FREE2m strongly correlated with intellectual functioning and autism features, however associations were not as strong for FXS females. Fragile X mental retardation 1 gene (FMR1) mRNA levels in blood were correlated with FREE2m in both NBS and DBS, for both sexes. In females, DNAm was significantly increased at birth with a decrease in childhood. The findings support the use of FREE2m analysis in newborns for screening, diagnostic and prognostic testing in FXS.

Application of Retinol-Binding Protein Enzyme Immunoassay to Dried Blood Spots to Assess Vitamin A Deficiency in a Population-Based Survey: The Uganda Demographic and Health Survey 2006

2008 ◽  
Vol 29 (4) ◽  
pp. 297-305 ◽  
Author(s):  
Rhona Kezabu Baingana ◽  
Denis Kasozi Matovu ◽  
Dean Garrett
Keyword(s):  
Vitamin A ◽  
Enzyme Immunoassay ◽  
Health Survey ◽  
Vitamin A Deficiency ◽  
Population Level ◽  
Dried Blood Spots ◽  
Retinol Binding Protein ◽  
Serum Retinol ◽  
Blood Spots ◽  
Resource Poor

Background Vitamin A deficiency is a public health problem in most developing countries. The technological challenges associated with the measurement of serum retinol have limited the epidemiologic assessment of vitamin A deficiency. The combination of retinol-binding protein (RBP) enzyme immunoassay and dried blood spots offers a rapid, inexpensive, and reliable tool for the population-level assessment of vitamin A deficiency in resource-poor settings. Objective To report on the application of RBP enzyme immunoassay and dried blood spots to assess serum retinol concentrations as an indicator of vitamin A status in the Uganda Demographic and Health Survey 2006. Methods A total of 5,642 capillary blood spot samples were collected by fingerprick onto filter paper cards from women (15–49 years) and children (6–59 months) in a representative probability sample of 9,864 households between May and October 2006. The cards were dried, packed individually with desiccant, and kept at 4°C in a portable refrigerator in the field and at –20°C in the laboratory. Prior to analysis, the RBP enzyme immunoassay was optimized with the use of matched serum and dried blood spots. Results The correlation between RBP values determined by matching serum and dried blood spots was excellent ( r = 0.79, p < .00001). The prevalence of vitamin A deficiency in women (RBP < 1.24 μmol/L) and children (RBP < 0.825 μmol/L) was 19.4% and 20.4%, respectively. Conclusions The combination of RBP enzyme immunoassay and dried blood spots is a simple, reliable, and cost-effective tool for the estimation of vitamin A deficiency in population-level surveys in resource-poor settings.

scholarly journals Retinol homeostasis in lambs given low and high intakes of vitamin A

1983 ◽  
Vol 50 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Susan Donoghue ◽  
David S. Kronfeld ◽  
David Sklan
Keyword(s):  
Vitamin A ◽  
Plasma Clearance ◽  
Basal Diet ◽  
Retinol Binding Protein ◽  
Faecal Excretion ◽  
Several Variables ◽  
Supplemental Vitamin ◽  
Retinyl Esters ◽  
Plasma Retinol ◽  
Retinol Concentration

1. Four groups of lambs were fed on a low-carotene basal diet. One group received no supplemental vitamin A (mildly deficient). Remaining groups were supplemented daily with vitamin A acetate equivalent to 100 (control) 9000 (mildly intoxicated) and 18000 (severely intoxicated) μg retinol/kg body-weight. After 16 weeks lambs received a bolus of[15−3H]retinol intravenously; blood, urine and faeces were sampled for 48 h.2. Plasma retinol was complexed to a protein of 20000 molecular weight (MW), which in turn was complexed to a protein of 65000 MW; these proteins correspond respectively to retinol-binding protein and prealbumin. Plasma retinol concentration reached plateau values in intoxicated lambs, but plasma retinyl ester concentrations increased rapidly when liver contents of both retinol and retinyl esters exceeded approximately 10 and 100 mg respectively and kidney contents of both retinol and retinyl esters exceeded 30 μg. Labelled compounds, more polar than retinol, were found in plasma; their concentration increased tenfold in intoxicated lambs within 48 h.3. Plasma retinol transport rates were 0·1, 10·5 and 11·8 times control values, and clearance rates were 0·3, 14·1 and 14·3 times control values in mildly-deficient, and mildly- or severely-intoxicated lambs respectively. Turnover of retinol increased rapidly when liver contents of retinol and retinyl esters exceeded approximately 10 and 100 mg respectively and kidney contents of both retinol and retinyl esters exceeded approximately 30 μg. Plasma clearance of retinyl esters was unchanged with intake. Faecal excretion of tracer increased linearly with plasma retinol clearance.4. Our findings identify, several variables that appear to be involved in retinol homeostasis, including plasma retinol clearance and excretion.

Effect of Citric Pectin on beta-Carotene Bioavailability in Rats

2002 ◽  
Vol 72 (4) ◽  
pp. 199-203 ◽  
Author(s):  
Márcia Zanutto ◽  
Alceu Jordão Júnior ◽  
Mônica Meirelles ◽  
Rosa Fávaro ◽  
Hélio Vannucchi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Vitamin A ◽  
High Performance ◽  
Wistar Rats ◽  
Beta Carotene ◽  
Retinyl Palmitate ◽  
Control Group ◽  
Plasma Retinol ◽  
Experimental Group ◽  
Retinol Concentration

The effect of citric pectin on the bioavailability of synthetic beta-carotene was studied. Thirty Wistar rats were used, ten animals were sacrificed at the beginning of the experiment and remaining animals were divided into two groups and received the following diets for 30 days: control group (CG) – 24 mg beta-carotene/g diet + 0% citric pectin; experimental group (EG) – 24 mugbeta-carotene/g diet + 7% citric pectin. Plasma and liver beta-carotene, vitamin A, and retinyl palmitate concentrations were determined by high-performance liquid chromatography (HPLC). Plasma retinol concentration was 1.42 ± 0.36 mumol/L for CG and 1.10 ± 0.24 mumol/L for EG (p = 0.1), and plasma beta-carotene concentration was 0.20 ± 2.51 mumol/L for CG and 0.07 ± 0.04 µumol/L for EG (p = 0.01). Only traces of retinyl palmitate were detected in CG and none in EG. Retinol did not differ significantly between groups CG and EG, while a significantly higher beta-carotene concentration was observed for CG. Liver concentrations of retinol (CG: 4.90 ± 2.51 µug/g; EG: 2.68 ± 1.12 µug/g), beta-carotene (CG: 0.98 ± 0.28 µug/g; EG: 0.11 ± 0.06 µug/g), and retinyl palmitate (CG: 95.47 ± 45.13 µug/g, EG: 37.01 ± 17.20 µug/g) differed significantly between groups (p < 0.05), with a lower concentration being observed for EG. We conclude that 7% citric pectin in the rat diet decreases the bioavailability of synthetic beta-carotene, reducing the liver reserves of vitamin A and beta-carotene.

scholarly journals Dynamics of conjunctival impression cytologic changes after vitamin A supplementation

1997 ◽  
Vol 77 (6) ◽  
pp. 863-869 ◽  
Author(s):  
Swapan Chowdhury ◽  
N. K. Ganguly ◽  
Minni Verma ◽  
Rajesh Kumar ◽  
Lata Kumar ◽  
...  
Keyword(s):  
Vitamin A ◽  
Oral Dose ◽  
Controlled Study ◽  
Impression Cytology ◽  
Double Blind ◽  
Vitamin A Supplementation ◽  
Double Blind Placebo ◽  
Future Studies ◽  
Plasma Retinol ◽  
Retinol Concentration

AbstractTo investigate the chronological changes in conjunctival epithelium after supplementation with a massive oral dose of vitamin A, conjunctival impression cytology (CIC) with transfer was carried out repeatedly among 200 children aged 6–120 months in a randomized, double-blind, placebo-controlled study in Chandigarh (India). Significant conversion to normal CIC started 71–80 d after vitamin A supplementation and by 101–110d conversion had taken place in all children. Compared with the placebo group, plasma retinol concentration at 100d post-supplement was found to be significantly higher in the vitamin A-supplemented group P = 0·04. This study demonstrates that CIC responds to a massive oral dose of vitamin A 3–4 months after supplementation. These findings should guide future studies and evaluations in which CIC is used to assess response to vitamin A interventions.

Vitamin A Inadequacy Observed in a Group of 2- to 6-Year-Old Children Living in Kwangju, Republic of Korea

2007 ◽  
Vol 77 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Kim ◽  
Giraud ◽  
Cho ◽  
Driskell
Keyword(s):  
Vitamin A ◽  
Plasma Concentrations ◽  
Republic Of Korea ◽  
Healthy Children ◽  
Dietary Intakes ◽  
Vitamin A Status ◽  
The Mean ◽  
Plasma Retinol ◽  
Food Recalls ◽  
Retinol Concentration

Dietary intakes and plasma concentrations of retinol and carotenoids were estimated in assessing the vitamin A status of young children in Kwangju, Republic of Korea. Three consecutive 24-hour food recalls and fasting blood samples were obtained from 123 healthy children (58 boys, 65 girls), aged 2–6 years. The daily vitamin A intake (mean ± SD) was 355.9 ± 178.1 μg retinol equivalents or 239.0 ± 111.2 μg retinol activity equivalents. Provitamin A carotenoid intakes were 1211.2 ± 840.0 μg/day β-carotene, 234.6 ± 231.7 μg/day α-carotene, and 149.1 ± 160.7 μg/day β-cryptoxanthin. Approximately 15–26% of subjects consumed < Korean Estimated Average Requirements (EAR) for vitamin A; whereas, 57–64% consumed < EAR for vitamin A for USA/Canadians. The mean plasma retinol concentration was 1.108 ± 0.244 μmol/L. There were no significant correlations between intakes and plasma concentrations of retinol and carotenoids. Only 2.4% of children were vitamin A-deficient based on having plasma retinol concentrations < 0.70 μmol/L. Plasma retinol concentrations of 42.3% of subjects were 0.70– < 1.05 μmol/L, which is considered indicative of potentially suboptimal vitamin A status. Therefore, some children may be at risk of inadequate vitamin A status in Kwangju, Republic of Korea.

scholarly journals Streptozotocin-induced diabetes in rats is associated with impaired metabolic availability of vitamin A (retinol)

1996 ◽  
Vol 75 (4) ◽  
pp. 615-622 ◽  
Author(s):  
P. J. Tuitoek ◽  
S. Ziari ◽  
A. T. C. Tsin ◽  
R. V. Rajotte ◽  
Miyoung Suh ◽  
...  
Keyword(s):  
Vitamin A ◽  
Wistar Rats ◽  
Plasma Concentrations ◽  
Basal Diet ◽  
Diabetic Rats ◽  
Lower Plasma ◽  
Vitamin A Supplementation ◽  
Streptozotocin Induced Diabetes ◽  
Plasma Retinol ◽  
Retinol Concentration

Using streptozotocin-induced diabetic Wistar rats, studies were carried out to examine the metabolic availability of vitamin A in the plasma, liver and the retina of the eye. Control and diabetic rats were fedad lib. on a semi-purified diet either with or without (basal) vitamin A supplementation, or pair-fed on the basal diet for 4 weeks. Despite the fact that diabeticrats consumed 48% more feed, they had lower plasma concentrations of retinol (P<0·003). The decrease in plasma retinol concentration was a response to diabetes (or diabetes-induced trauma), since neither pair-feeding (P<0·01) nor vitamin A supplementation altered this effect (P<0·05). Furthermore, the hepatic concentrations of the vitamin in these animals remained elevated and this increase was greater in the supplemented diabetic group (P<0·001). Decreases in 11-cis retinal (a component of rhodopsin) concentrations in the retina were also observed in diabetic animals. The increased hepatic and the decreased plasma and retina vitamin Alevels suggest a defect in the transport of the vitamin from the liver.

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